The present invention concerns an input/output module of the type which includes an insulating housing that can be fastened to a support rail, connecting terminals for wiring, and electrical components that are arranged on a printed circuit board. Such input/output modules are known, for example, from German application DE-A 4,402,001 (corresponding to U.S. Pat. No. 5,641,313) as well as German application DE-A 4,402,002.
In particular it is known to arrange several input/output modules (I/O modules) side-by-side on support rails so that they can be housed, for example, in switch cabinets. These side-by-side arranged I/O modules are then connected mechanically and electrically. In that case, only the first module, meaning a base module or bus coupler, contains a bus-coupling component, which establishes the logical connection between a bus and the I/O modules. This is known, for example, for an interior installation from German DE-C 19,605,698. Problematic in this case is the accessibility of the individual modules for replacement and service purposes. In particular, it is always necessary to completely dismantle the wiring, resulting in a high labor and assembly expenditure.